Embodiments of the invention relate generally to superhard elements, particularly but not exclusively for machining superalloy material, method of making same and method for using same.
A superalloy is an alloy that exhibits excellent mechanical strength and creep resistance at high temperatures, good surface stability, and corrosion and oxidation resistance. The base alloying element is usually nickel, cobalt, or a nickel-iron alloy. Typical applications are in the aerospace, industrial gas turbine and marine turbine industries. An example of a kind of superalloys is austenitic nickel-chromium-based (Ni—Cr) superalloys. Many superalloys, particularly Ni—Cr superalloys, are difficult to machine using traditional techniques due to rapid work hardening. There is a need to provide materials for machine tools for more efficient machining of superalloy materials. In particular, there is a need to provide tools having extended working life when used to machine bodies comprising superalloy materials.
European patent publication number 0 699 642 discloses polycrystalline cubic boron nitride and polycrystalline diamond that are permeated with whiskers and/or fibers, in which the whisker content may comprise anywhere from almost zero to about 30 percent of the total weight of the cBN compact. The cBN content of the compact should be at least 60 weight percent. Consequently, the content of the whiskers in the non-cBN component of the material may be from almost zero to about 75 weight percent, although fewer whiskers result in a compact having less of the desirable qualities the whiskers provide.